What exactly is a multi-channel ADC?

[currentmirror2000]

Hi all, can anybody tell me what is exactly multi-channel ADC? just put multi-ADC in one chip? then what's the challenging point of putting multi-channel ADC in one chip?

i just searched the web and found TI has max 19-channel one and Analog Devices has max 16-channel. i am trying to find out the possibility of putting more channels, is that possible? and is there any commercial company producing such thing or better than TI and Analog Devices?

thanks in advance!

 

[DrWhoF]

Re: Question on ADC

You have to keep in mind that in most cases a multi-channel A/D converter is in fact single channel with multiplexed inputs so the conversion time for all channels will be multiplication of single channel and you can do one channel at a time.

 

[vdaniel]

Re: Question on ADC

Yes, the most of multichannel ADCs consist of one ADC, one Sample/Hold (if any) and one multiplexer.
But there exist a real multichannel ADCs, for example ADS7861 from Texas Instruments, which has inside two ADC, each equipped with its own Sample/Hold and 2x1 multiplexer. So you can simulteneously sample two channels, for example V (voltage) and I (current) and then multiply two codes in microcontroller or PC and get a real instant power.
There is a similar chip of Analog Devices to (I do not remember the type).

Varuzhan